Artificial slate



UNITED STATES PATENT OFFICE.

ER EsT FAHRIG, or PHILADELPHIA, PENNSYLVANIA, ASSIGNOR 0F ONE-HALF TO A. 1). CLARK, 0P PHILADELPHIA, PENNSYLVANIA.

ARTIFICIAL SLATE.

No Drawing.

To all whom it may concern Be it known that I, ERNEST F AHRIG, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented Artificial Slate, of which the following is a specification.

One object of my invention is to provide a novel composition primarily intended to possess the qualities of and serve as a substitute for slate and which may be capable of being turned, polished and otherwise worked into any desired shapes, which shall be a good insulator, oil, acid and fire proof, hard, durable, structurally strong and water resisting.

I further desire to provide a composition which while having the above noted qualities shall consist largely of slate, thus making it possible to utilize slate waste.

In the preferred form of my invention I prepare an intimate mixture of the following ingredients, in the specified proportions by weight, viz.,-slate 41%, sulfur 15%, quartzite, 11%, magnesite 10%, talc 9%, kaolin 8% and sericite 6%. Each of these ingredients prior to mixture is first crushed to a half inch size and is then screened, after which it is operated on in a tube mill or other suitable pulverizing machine whereby it is reduced to such a fineness that it will all pass through a one-hundred or higher mesh sieve. After being thus pulverized the materials specified are preferably stored separately in suitable bins where they are maintained in a dry condition.

When it is desired to prepare a batchof the particular compound forming my invention, I charge a tube mill, for example, with the necessary weights of the above noted ingredients in the proportions specified and operate such mill until said materials are so intimately mixed that an analysis of the product delivered shows that said in- Specification of Letters Patent. Patented De 14 1920.

Application filed December 10, 1919. Serial No. 343,961.

gredients are present in the proportions de sired. When the mixing operation is con. plete, the finely pulverized mixture has added t01 it a suitable binder such as a lution of one part aluminum chlorid and two parts magnesium chlorid having a specific gravity of 1.2;, or higher, which is employed in such quantitiesas to render the product sufficiently plastic to permit it to be molded, pressed, cast or otherwise shaped to the form desired.

After being thus shaped the compound is allowed to dry or set until it has attained the desired hardness, when it may be turned, polished, sawed or otherwise worked into a desired form such as roofing or other tiles, blocks for use in walls or partitions, tool handles, containers, etc.

Obviously other binders such as sodium 3. A composition of matter consisting of v substantially 41% slate, 15% sulfur, 11% quartzite, 10% magnesite, 9% talc, 8% kaolin, 6% sericite, and a binder.

4. A composition of matter consisting mainly of slate and sulfur with other inert ingredients all in a powdered condition and a binder.

ERNEST FAHRIG. 

